Herbert a



v of Georgia, and

' vessel,

enonem, AND HARRY n. GIBBS,

PROCESS FOR THE MANUFACTURE OF CYMENE SULFONIO ACIDS.

1,316,823, Specification o1 Letters Patent. No Drawing.

Application filed March 21, 1919. Serial Ho.

Patented Sept. 23,1919. 284,225.

(FILED UNDER THE ACT OF MARCH 3, 1883, 22 STAT. L, 625.)

To all whom it may concern:

Be it known that we, Josnrn A. HERBERT A. LUBS and HARRY D. GrBBs, citizens of the United States of America, and employees of the Department of Agriculture, reslding in the city of Norwich, county of New London, State of Connecticut, in the city of Savannah, county of Ohatham, State in the c1ty of San Francisco, Francisco, State of Calirespectively, (whose post-oflice address is Washington, D.. 0., have ointly invented a new and useful rocess for the Manufacture of Cymene Sulfonic Acids.

is application is made under the act of March 3, 1883, chapter 143 (22 Stat, 625),, and the invention herein described and claimed may be used by the Government of the United States or' any of its ofiicers or employees in the prosecution of work for e Government, or any person in the United States, without payment to us of any royaltv thereon.

' eretofore the sulfonic acids of cymene havebeen 'made only in small quantities biv dissolvin the cymene in concentrated su ric aci We have found that when cymene is sulfonated in the .gaseous state, and the products removed rapidly from the reaction much less sulfuric acid is necessary for the sulfonation.

We shall illustrate our invention by describing the process for the manufacture of cymene disulfonic acid, although the invention is not restricted to this particular sulfonic acid.

county of San fornia,

Sulfuric acid of specific gravity 1.84 is caused to descend over bafiie-plates, pebbles or coarse pumice stones, in atower, which is heated and maintained at a temperature of 180 to 190 centigrade. Para-cymene is heated to boiling and its vapors are passed up through the tower. The vapors come into contact with the descending hot sulfuric acid and are completely absorbed by it, with the formation of water and cymene disulfonic acids. The water escapes from the tower as steam and may be condensed in any suitable condenser attached at or near the top of the tower. The sulfonic acids, together with a slight excess of unused sulfuric acid, are carried downward by means AMBLER, I

' siderable amount of of gravity, and discharged from the bottom of the tower. The

product contains a concymene-Q-sulfonic acid, which is separated from the disulfonic acid ll known means, such as, for example,

the formation of the barium salts by neutralizing with barium carbonate, filtering the solution of the salts of the sulfonic acids from the barium sulfate and concentrating the vapor to crystallization, when the barium salt of the mono sulfonicacid of cymene separates first, leaving the barium salt of the disulfonic acid in solution from which it may be obtained by the addition of alcohol.

' Thus our invention furnishes a ready means of manufacturing the sulfonic acids of cymene in a continuous and automatic manner, and uslng less sulfuric acid than is commonly employed in sulfonation processes.

It is obvious that other concentrations of sulfuric acid than that having specific gravity 1.85 may be used, that other temperatures than 180 to 190 may be used, and that other acids than cymene disulfonic acid and cymene sulfonic acid may be manufacured by this method, and our invention is not restricted to such sulfuric acid, temperature,-or cymene sulfonic acid, but has a general application to the sulfonation of cymene in the gaseous state.

aving thus described our invention, we claim 1. A continuous ture of sulfonic acids of cymene by causing the vapors of cymene to mix with the vapors of sulfuric acid.

continuous processs for the manufacture of sulfonic acids of cymene by causing the vapors of cymene to come into contact with a descending current of sulfuric acid.

continuous process for the manufacture of sulfonic acids of cymene by causing the vapors of cymene to come into ture of sulfonic acids of cymene by causing the vapors of cymene to rise through a tower m which a stream of sulfuric acid 18 descendprocess for the manufacifn lover obstructions to break and retard its 5. A continuous process for the manufacture of sulfonic acids of cymene by causing the vapors of cymene to rise through a tower in which a stream of sulfuric acid, heated and maintained at a temperature at least approximately as high as that at which cymene boils, is descending over obstructions to break and retard its fall.

6. A continuous process for the manufacture of cymene-Q-sulfonic acid by causing the vapors of cymene to rise through a tower in which a stream of sulfuric acid, heated and maintained at a temperature at least approximately as high as that at which cymene boils, is descendin over obstructions to break and retard its fa l.

7. A continuous process for the manufacture of sulfonic acids of cymene by causing the vapors of cymene to rise through a tower in which a partial vacuum is maintained while a stream of sulfuric acid, heated and maintained at a temperature at least approximately as high as that at which cymene boils in said partial Vacuum, is descending over obstructions to break and retard'its fall.

In testimony whereof, we aifix our signatures in the presence of two subscribing wit nesses.

JOSEPH A. AMBLER. HERBERT A. LUBS. HARRY D. GIBBS.

Witnesses:

LOUIS E. WISE, LAURA A. SKIIN'NER. 

